响应面法优化成曲蚕豆瓣子中黄曲霉毒素B1的提取

郫县豆瓣中所用蚕豆是产自四川省和云南省的优质干蚕豆,经筛选、浸泡、接种、制曲等一系列加工后形成成曲蚕豆瓣子。采用酶联免疫吸附法(ELISA),根据Box-Behnken Design软件的设计原理,检测成曲蚕豆瓣子中黄曲霉毒素B1。探讨了甲醇浓度、料液比、超声波提取时间等因素对样品中黄曲霉毒素提取的影响,以确定检测生产过程中样品黄曲霉毒素含量的最优方案。以黄曲霉毒素含量为响应值,利用响应面分析法对提取参数进行优化。结果表明:甲醇浓度39.66%,超声波提取时间27.70min,超声波提取功率88.97%是检测成曲蚕豆瓣子中黄曲霉毒素含量的最优条件,以该优化条件检测成曲蚕豆豆瓣子中黄曲霉毒素其值达到最大,为1.47μg/kg。     

花生中黄曲霉毒素B_1提取方法的优化

主要研究了酶联免疫法检测花生中黄曲霉毒素B_1的提取条件,通过单因素试验分别研究料液比、甲醇体积分数、提取时间和超声波功率对黄曲霉毒素B_1提取效果的影响,通过正交试验法确定花生中黄曲霉毒素B_1的最佳提取条件。结果表明,各因素影响花生中提取黄曲霉毒素B_1含量的大小为:超声波功率甲醇体积分数提取的时间物料比。最佳提取条件为:料液比为1︰5 g/m L,甲醇体积分数60%,提取时间为11 min,超声波功率70 W。试验以为花生中黄曲霉毒素B1的检测提供简便、可靠、准确的分析方法。     

大曲中黄曲霉毒素B_1提取方法的研究

主要探讨了酶联免疫法检测大曲中黄曲霉毒素B1的提取条件;分别考察了超声波提取时间、超声波提取功率、甲醇浓度对黄曲霉毒素B1提取效果的影响;用正交设计找出了最佳工艺参数:甲醇浓度为55%(v/v),提取时间为25 min,提取功率为200 W。采用本提取工艺所得黄曲霉毒素B1提取率明显高于国标。本研究可为大曲中黄曲霉毒素B1的检测提供简便、准确、可靠的分析方法。     

响应面法优化大曲中黄曲霉毒素B1提取工艺

该研究利用单因素试验和响应面法对大曲中黄曲霉毒素B1（AFB1）的提取条件进行优化,分别考察了甲醇体积分数、超声波提取功率、提取时间和提取温度对AFB1提取效果的影响。结果表明,大曲中AFB1的最佳提取工艺为甲醇体积分数55%、超声波功率为200 W、提取时间为25 min、提取温度30 ℃。在此最优条件下,AFB1得率为2.58 μg/kg,可为大曲中AFB1的提取提供简便、准确、可靠的分析方法。     

柠檬酸对花生B族黄曲霉毒素脱毒效果的研究

研究分析不同浓度的柠檬酸溶液在不同的液料比和不同作用时间下花生中B族黄曲霉毒素的含量变化。结果表明,随着柠檬酸溶液浓度的提高,液料比的增加,作用时间的延长,花生中B 族黄曲霉毒素的含量降低,脱毒效果越好。用80g/L 的柠檬酸溶液,液料比(V/m)为5:1 对霉变后染有B 族黄曲霉毒素(AFB1 和AFB2)的花生颗粒(98.60μg/kg)浸泡30min 具有很好的脱毒效果,处理后,黄曲霉毒素含量小于20μg/kg,达到国标GB2761 - 2005 对花生中黄曲霉毒素限量的要求。     

响应曲面法优化茶树总黄酮提取工艺的研究

以广东茶树枝叶为原料,利用超声波辅助提取茶树总黄酮,并采用Box-Behnken对超声波超声时间、乙醇浓度、料液比进行响应面优化。结果表明:最佳提取工艺参数为乙醇浓度60%,料液比1∶30(g/m L),提取时间40 min。在此条件下,总黄酮的得率为29.7 mg/g,超声提取工艺合理、可行,为茶树总黄酮的进一步开发利用提供参考依据。     

超声波辅助提取九香虫黄酮化合物的工艺研究

以乙醇为溶剂,以超声波作为提取辅助设备,通过单因子试验确定影响黄酮化合物提取的主要因素及其最佳水平范围,通过L9(34)正交试验确定其最优提取条件,研究超声波辅助提取九香虫黄酮类化合物的最优工艺。最优工艺条件是料液比1:30、提取时间30 min、乙醇浓度70%、提取温度60℃。在最优工艺条件下测得样品中黄酮类化合物的含量达最大,为17.1 mg.g-1。影响超声波辅助提取九香虫黄酮化合物的因素主次为料液比>提取时间>醇浓度>提取温度。     

桔梗中桔梗总皂苷和桔梗皂苷D的超声波提取工艺

分别以水和甲醇为提取溶剂,研究超声波法提取桔梗中桔梗总皂苷和桔梗皂苷D的工艺条件。采用正交试验法,考察提取次数(A)、料液比(B)、提取时间(C)、超声功率(D)对桔梗总皂苷和桔梗皂苷D提取率的影响。以水为提取溶剂时,超声提取桔梗总皂苷的影响顺序:提取次数>超声功率>料液比>提取时间,最优组合A3B3C3D2;提取桔梗皂苷D的影响顺序:超声功率>料液比>提取次数>提取时间,最优组合A2B3C1D1。以甲醇为提取溶剂时,超声提取桔梗总皂苷的影响顺序:提取次数>超声功率>提取时间>料液比,最优组合A3B2C1D3;提取桔梗皂苷D的影响顺序:提取时间>提取次数>料液比>超声功率,最优组合A2B1C2D3。     

响应面法优化牛膝中齐墩果酸超声波辅助提取工艺

以牛膝为原料,以齐墩果酸提取得率为指标,采用超声波辅助提取牛膝中齐墩果酸。分别研究了乙醇浓度、料液比、提取时间对齐墩果酸提取得率的影响,通过响应面实验优化了提取工艺。结果表明,齐墩果酸提取的较佳工艺条件是:乙醇浓度70%,提取时间20min,料液比(w/v)1∶20。在此条件下,齐墩果酸的提取含量为11.14mg/g。     

纤维素提取过程中半纤维素去除工艺研究

狗牙根中纤维素的含量非常丰富,以狗牙根为原料进行纤维素的提取,有利于各种草类的有效利用。本文以狗牙根为原料,采用超声波辅助碱法提取狗牙根纤维素,探索纤维素提取过程中半纤维素去除的最优工艺。分别分析了氢氧化钠浓度、料液比、超声波处理的温度、超声波处理的功率、超声波处理的时间等因素对纤维素得率的影响,进而设计正交试验,探索最佳条件。实验结果显示:狗牙根纤维素提取中,半纤维素去除的最佳工艺为料液比1∶15,氢氧化钠浓度3%,超声波处理温度35℃,超声波处理时间6 h,超声波处理功率100 W,此时粗纤维素得率为30.18%。     

No effect of soybean lipoxygenase on aflatoxin production in Aspergillus flavus-inoculated seeds

Soybean lines lacking lipoxygenase (LOX) activity were compared with soybean lines having LOX activity for the ability to support growth and aflatoxin B1 production by the fungal seed pathogen Aspergillus flavus. Whole seeds, broken seeds, and heat-treated (autoclaved) whole seeds were compared. Broken seeds, irrespective of LOX presence, supported excellent fungal growth and the highest aflatoxin levels. Autoclaved whole seeds, with or without LOX, produced good fungal growth and aflatoxin levels approaching those of broken seeds. Whole soybean seeds supported sparse fungal growth and relatively low aflatoxin levels. There was no significant difference in aflatoxin production between whole soybean seeds either with or without LOX, although there did seem to be differences among the cultivars tested. The heat treatment eliminated LOX activity (in LOX+ lines), yet aflatoxin levels did not change substantially from the broken seed treatment. Broken soybean seeds possessed LOX activity (in LOX+ lines) and yet yielded the highest aflatoxin levels. The presence of active LOX did not seem to play the determinant role in the susceptibility of soybean seeds to fungal pathogens. Seed coat integrity and seed viability seem to be more important characteristics in soybean seed resistance to aflatoxin contamination. Soybean seeds lacking LOX seem safe from the threat of increased seed pathogen susceptibility.     

4种黄曲霉毒素B1酶联免疫试剂盒 与液相法检测结果比较

摘 要：目的 综合评价4 种不同厂家的黄曲霉毒素B1试剂盒。方法 选择几种食品基质（婴幼儿米粉、花生酱、酱油）,分别用R-Biopharm,Romer,Helica和华安麦科的黄曲霉毒素B1试剂盒检测,将测定结果与液相色谱法测得结果进行比对。结果 通过与液相色谱法测得结果比较,华安麦科试剂盒只适合检测婴幼儿米粉样品。Helica和R-Biopharm试剂盒能检测多种基质,而Helica试剂盒检测结果与液相相符度低,R-Biopharm试剂盒检测米粉时,本底较高。Romer试剂盒适用于花生酱和酱油样品。结论 为了得到最佳的检测结果,针对不同的样品基质,应选择合适的试剂盒。当用酶联法检测出阳性样品时,需用液相色谱法确认。     

酶联免疫法测定不同食用植物油中黄曲霉毒素B_1

用酶联免疫法(ELISA)测定食用植物油中黄曲霉毒素B1,并对如何防控食用油中黄曲霉毒素B1进行探讨。在所分析菜籽油、大豆油、花生油、核桃油4种油中,以菜籽油黄曲霉毒素B1含量最低,其次是大豆油和核桃油,花生油含量最高。方法检测灵敏度为0.1μg/kg,平均回收率为91.4%～93.5%,相对标准偏差小于5%;结果表明,酶联免疫法测定准确,稳定性和重现性好,可广泛用于食用植物油黄曲霉毒素B1检测。     

不同品牌霉菌毒素检测试剂盒的质量评价

目的评价当前国内外应用较广的9个不同品牌黄曲霉毒素B1、玉米赤霉烯酮、呕吐毒素检测试剂盒的准确性。方法选取3种不同浓度的质控样品、4种饲料原料样品(玉米干全酒精糟、玉米胚芽粕、麦麸、豆粕)、2种饲料产品样品(蛋鸡配合饲料、牛浓缩饲料)。采用3种不同浓度的质控样(用萃取液点板6个孔)的检测结果变异系数(variable coefficient, CV)作为精密度评价指标。采用质控样的6个单独检测结果变异系数作为系统的精密度评价指标,采用实际样品的检测结果评价试剂盒的适用性。结果呕吐毒素试剂盒CV值平均值2号品牌2.7%, 3号品牌3.4%。玉米赤霉烯酮试剂盒CV值平均值3号品牌4.6%, 2号品牌5.5%, 4号品牌5.4%。黄曲霉毒素B1试剂盒CV值平均值5号品牌3.3%, 8号品牌3.7%, 2号品牌4.1%。结论依据试剂盒精密度、准确度、灵敏度和适应性综合评估2号品牌呕吐毒素试剂盒综合结果优秀, 9号品牌玉米赤霉烯酮试剂盒综合结果较好, 5号品牌黄曲霉毒素B1综合结果较好。同时,就检测上述3种常见毒素而言,没有发现一个品牌的试剂盒可以同时在多个毒素检测上表现优秀。     

Reduction of aflatoxins by Korean soybean paste and its effect on cytotoxicity and reproductive toxicity--part 2. Antigenotoxic effects of the methanol extract of Korean soybean paste (doen-jang) on aflatoxin B1-induced bacterial reverse mutation and chromosome aberration

A bacterial reverse-mutation assay with Salmonella Typhimurium TA1535, TA1537, TA98, TA100, and TA102 and an in vitro chromosome aberration assay with Chinese hamster lung (CHL) cells were used to investigate the genotoxicity of the methanol extract of Korean soybean paste (doen-jang [dwen-jahng]) and its antigenotoxic activity against aflatoxin B1. The methanol extract revealed nonmutagenic potential for all of the bacterial strains tested. The extract significantly reduced the numbers of revertants per plate when it was added to the assay system with Salmonella Typhimurium TA100 (P < 0.05). The extract also exhibited significant inhibitory effects on chromosome aberration in CHL cells (P < 0.05). The findings of this work indicate that the methanol extract of Korean soybean paste could have strong potential as an antigenotoxic material.     

酶联免疫法检测混合植物油中黄曲霉毒素B1的含量

目的建立酶联免疫法测定混合植物油中黄曲霉毒素B_1含量的分析方法。方法采用直接竞争酶联免疫吸附法对样品进行测定。样品经甲醇溶液提取,提取的抗原及黄曲霉毒素B_1标记物与微孔板上的黄曲霉毒素B_1特异性单克隆抗体竞争结合,洗涤除去未结合杂质。将底物加入孵育,产生蓝色产物,加入终止液终止反应蓝色产物变成黄色产物,450nm处测量吸光度。结果本方法在2h内完成混合植物油中黄曲霉毒素B_1含量的测定。黄曲霉毒素B_1的加标浓度在1.0～20.0μg/kg之间时的回收率为76.5%～120.2%,方法定量限为1.00μg/kg。结论该方法快速、准确、灵敏,适合测定混合植物油中黄曲霉毒素B_1。     

The preparation, validation and certification of the aflatoxin content of two peanut butter reference materials.

The preparation of two peanut butter reference materials and the certification of their aflatoxins B1, B2, G1, G2 and total aflatoxin contents is described. The materials were prepared and certified within the BCR Programme of the Commission of the European Community as part of a broad activity to improve accuracy and agreement of measurements of importance in food and agriculture (Wagstaffe and Belliardo 1990). Reference material RM 385 was prepared from naturally contaminated peanuts, roasted and ground into a paste and then blended with uncontaminated peanut butter to achieve the desired aflatoxin concentrations. Details are given of the blending and canning procedure, and the checks to ensure homogeneity and stability of the material. Reference material RM 401 was similarly prepared but from an uncontaminated peanut butter. The certification exercise was carried out by nine laboratories using a variety of extraction and clean-up procedures, but all using high performance liquid chromatography (HPLC) as the determinative stage although operating under a variety of chromatographic conditions. RM 385 was certified as containing aflatoxins B1, B2, G1 and G2 at levels of 7.0 +/- 0.8 micrograms/kg, 1.1 +/- 0.2 micrograms/kg, 1.7 +/- 0.3 micrograms/kg and 0.3 +/- 0.2 micrograms/kg respectively (total aflatoxin content of 10.1 +/- 1.5 micrograms/kg) and RM 401 as containing aflatoxin B1, B2 and G2 at less than 0.2 micrograms/kg and aflatoxin G1 at less than 0.3 micrograms/kg (total aflatoxin content less than 0.9 micrograms/kg). The materials are intended for the verification of methods used to determine aflatoxins in nuts and nut products.     

Responses of dairy cows to dietary aflatoxin: feed intake and yield, toxin content, and quality of milk of cows treated with pure and impure aflatoxin

Ten fistulated Holstein cows in midlactation were given daily doses of 13 mg of aflatoxin B1 for 7 days. Six received pure aflatoxin B1; three received an impure preparation that contained aflatoxin B1 plus other aflatoxins and metabolites produced by Aspergillus parasiticus in culture. Toxin was administered to each animal twice daily, one-half of the total dose each time, via the rumen orifice. Morning and evening milks were collected and analyzed for aflatoxin M1. Milk production and feed intake were monitored for 5 days before, every day during, and for 8 days after treatment with aflatoxin B1. Milk contained from 1.05 ppb to 10.58 ppb of aflatoxin M1. None was in milk 4 days after administration of toxin had stopped. Somatic cell counts and standard plate counts from milks of two cows were not affected appreciably by administration of toxin. Fluctuations in feed intake and milk production occurred in all animals during the treatment period with a significant decrease in milk production of those cows receiving 13 mg of impure aflatoxin B1 per day. Differences in results when cows received equal amounts of aflatoxin B1 may be attributable to the type of toxin administered (pure versus impure).     

Reduction of aflatoxins by Korean soybean paste and its effect on cytotoxicity and reproductive toxicity--Part 3. Inhibitory effects of Korean soybean paste (doen-jang) on aflatoxin toxicity in laying hens and aflatoxin accumulation in their eggs

This study was conducted to determine the effects of Korean soybean paste (doen-jang [dwen-jahng]) (at concentrations of 0.5, 1, and 5%) on the toxicity of 500 ppb of aflatoxin in the diets of 60 laying hens (Isa Brown) divided into five groups and treated from week 15 to week 67. The aflatoxin-treated hens exhibited many deleterious effects, including reduced body weight; increased relative organ weights; decreased egg production; aflatoxin accumulation in eggs; decreased serum calcium, phosphorus, and alanino amonotransferase (ALT) levels; increased serum gammaglutamil transferase and lactic dehydrogenase levels; and, most significantly, severely altered cell foci and sinusoid dilatation in the liver, relative to control hens. The feeding of 1% soybean paste to hens reduced the adverse effects of aflatoxin on body weight, relative organ weights, egg production, and aflatoxin accumulation in eggs and improved serum calcium and ALT levels and the histopathological lesions of the liver. The feeding of 5% soybean paste to hens resulted in higher levels of the same types of improvements, especially with regard to the histopathological findings for the liver. On the basis of these results, it was suggested that a diet including 5% (and in some cases only 1%) Korean soybean paste protected laying hens and their eggs from the major deleterious effects of 500 microg of aflatoxin per kg of diet and from aflatoxin accumulation. These results indicate that dietary supplementation with Korean soybean paste reduces aflatoxin toxicity in laying hens that ultimately produce human foods such as eggs and poultry.